The theme is a lonely girl living in the countryside without knowing the rest of the world. She has a feeling of nostalgia and healing. She is trying to do her best to discover the city to find happiness.

This book celebrates the 15th anniversary of Hello! Project. As its title suggests, it is a guidebook on the songs released by current (Morning Musume, Berryz Kobo, °C-ute, S/mileage, Juice=Juice) and former groups and members (T&C Bomber, Melon Kinenbi, Matsuura Aya, Mano Erina, …), and sub-units (Tanpopo, Petit Moni…) of Hello! Project.

It gives many details about 446 singles including the photos of the covers and the names of the songwriters.

The DVD and the Blu-ray contain all the songs and MCs performed during ManoEri’s last solo live. They also include her graduation ceremony from Hello! Project featuring Tsugunaga Momoko (Berryz Kōbō) and Yajima Maimi (°C-ute) as special guests. Hello! Project Kenshuusei members, including Miyamoto Karin and Takagi Sayuki from Juice=Juice, appeared as backdancers.